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From Breast Cancer to the Epstein-Barr Virus, Cancer Vaccines are a Game Changer

October is National Breast Cancer Awareness Month and, as such, it is time to shed some light on important breast cancer research. In 2010, Dr. Vincent Tuohy and colleagues from the Cleveland Clinic published a paper in Nature Medicine that shows a vaccine using the target protein alpha-lactalbumin was able to prevent breast cancer in 100 percent of animal models.

While most cancer vaccines have had a more therapeutic effect against already grown tumors in the past, this breast cancer vaccine is preventative and stops the formation of cancer. Along with preventing breast cancer formation, this vaccine was also able to slow the growth of already-existing tumors in mouse models.

The protein alpha-lactalbumin was chosen because it is expressed in high rates in most human breast tumors. It is also expressed in mammary epithelial cells but only when a woman is lactating. This means that the vaccine may be safely used after a woman has children during her premenopausal, post-childbearing years.

There are a variety of challenges that developing preventive cancer vaccines poses, according to a review in Nature Immunology. This includes attempting to determine which antigen and adjuvant is best to use for treating a particular cancer, what immune response to produce, and how to ensure long-lasting immunity.

Cancer vaccines also need to overcome the immune suppression a tumor may present. When attempting to prevent cancer formation, a vaccine must influence long-term immune system memory without leading to autoimmunity. Due to these difficulties, developing effective cancer vaccines has been arduous for many scientists around the world.

Researchers from across the United States have also been working on developing a vaccine against the Epstein-Barr Virus (EBV). The Epstein-Barr Virus is linked to a number of different cancers such as Hodgkin’s lymphoma and nasopharyngeal carcinoma.

Three years ago, scientists from academia, industry, and the government met at a conference held by the U.S. National Institutes of Health to discuss the benefits and difficulties of developing a vaccine for EBV, according to the Science Translational Medicine journal. This virus is associated with a variety of different diseases and infects at least 90 percent of the population.

The majority of efforts for developing an EBV vaccine have focused on using the glycoprotein gp350 as its target due its high abundance within the virus and infected cells. However, two major clinical trials using an EBV vaccine and this glycoprotein as a target did not succeed and led to poor immunogenicity.

Nonetheless, there are therapeutic vaccines being developed to treat malignancies related to the Epstein-Barr Virus. These immunotherapies focus on T cell–mediated immunity for targeting the proteins present in tumor cells infected by EBV.

Animal models have also been used within EBV research. Nonhuman pcanrimates like rhesus monkeys and cotton-top tamarin monkeys were included in preclinical trials. The tamarin monkeys, for instance, were injected with gp350, which protected the primates from EBV-induced B cell lymphomas. Animal models are clearly useful and necessary during cancer vaccine development and the many stages of pre-clinical drug production.